KR100707477B1 - A variable sample pulse generator and a electric filed strength measuring equipment containing it - Google Patents

Abstract

The present invention relates to a variable sample pulse generating device for measuring the received power of a fast fading signal of a mobile radio signal and an electric field strength measuring device including the same, in order to more accurately measure a fast fading signal of a mobile radio signal, The present invention relates to a variable sample pulse generating device for increasing the sampling rate of an analog-to-digital converter by extending a desired number of sample data between pulses and a pulse, and an electric field strength measuring device for measuring the intensity of a received electric field according to each position.

A receiving field strength measuring apparatus for measuring a reception power of a fast fading signal of a mobile radio signal of the present invention includes a field strength receiver for receiving a fading signal of a mobile communication channel through an antenna and an analog output signal of the field strength receiver as a digital signal. Analog-to-digital conversion unit (A / D conversion unit) for converting, a pulse generator for providing a pulse at regular intervals according to the number of revolutions of the wheel of the moving object spatially, and accurately receive the power of the fast fading signal of the mobile radio signal By measuring the time interval and the amount of time change between the pulse and the pulse generator of the pulse generator so as to receive the data at a constant spatial interval even if the speed of the moving object changes, by adjusting the data measurement time interval of each pulse interval, GPS antenna, variable sample controller for adjusting sampling rate of digital converter It includes data storage for storing the output of the position data of the digital conversion output portion of the electric field intensity data and the GPS receiving unit at the same time - via the GPS receiver, and the analog receiving the GPS data.

Mobile communication fading signal, receiving field strength measuring device, variable sample pulse generator

Description

VARIABLE SAMPLE PULSE GENERATOR AND A ELECTRIC FILED STRENGTH MEASURING EQUIPMENT CONTAINING IT}

1 is a diagram showing the electric field strength of a radio wave signal including path loss, long-term fading, and short-term fading.

2 is a block diagram of an electric field strength measuring apparatus for measuring a fast fading signal of a mobile radio signal according to a preferred embodiment of the present invention.

3 is a pulse waveform of a conventional general pulse generator, and is a diagram of a pulse waveform of a pulse generator that generates four pulses per one revolution of a moving wheel.

4 is a diagram of measurement of received data in a moving body moving at the same speed.

5 is an algorithm illustrating a principle of acquiring received field strength data at a constant spatial interval even when the speed of a moving object is not constant according to a preferred embodiment of the present invention.

FIG. 6 is a data distribution measured when the speed of a moving object is changed by the algorithm of FIG. 5 according to an exemplary embodiment of the present invention.

〈About the main part of the drawings〉

100: antenna 200: field strength receiver

300: A / D converter 400: pulse generator

500: variable sample control unit 600: GPS antenna

700: GPS 800: data storage

The present invention relates to a variable sample pulse generator for measuring the reception power of a fast fading signal of a mobile radio signal, and an electric field strength measuring device including the same. In order to more accurately measure a fast fading signal of a mobile radio signal, The present invention relates to a variable sample pulse generating device for increasing the sampling rate of an analog-to-digital converter by extending a desired number of sample data between pulses and a pulse, and an electric field strength measuring device for measuring the intensity of a received electric field according to each position.

The mobile radio signal has multiple reflections caused by irregular terrain and diffraction and reflection caused by numerous obstacles. Therefore, the mobile propagation signal received by the antenna of the receiver is a composite wave of several waves having different amplitudes and phases, and the amplitude, phase, and frequency of the received synthesized wave have a random characteristic represented by a probability distribution. to be.

Until now, the apparatus for measuring fading signal showing the change of mobile radio signal is electric field strength measuring device or spectrum analyzer, DM (Diagonostic Monitor) which is a software tool for CDMA radio wave measurement. Since only distribution characteristics can be measured, there is a limit to accurate measurement and analysis of channel characteristics of mobile radio signals that vary according to the environment around the receiver.

The propagation characteristics of the mobile radio signal are greatly influenced by the physical environment of the propagated region as well as the frequency of the signal. Therefore, in order to evaluate the performance of the existing system and to develop a new system, the theoretical study of the propagation characteristics for various propagation environments and mobile radio signal measurement and analysis in the actual environment should be performed in parallel.

In the mobile communication environment, it is very difficult to accurately predict the received field strength. In particular, in the radio environment where communication is mainly based on reflected waves rather than direct waves, such as urban areas, the strength of the received field strength varies greatly even if the receiving point changes only a little. As such, the prediction of the electric field strength according to the change of the surrounding environment is difficult to interpret by the general propagation model. Therefore, the empirical equations presented by measuring and analyzing the actual signals are frequently used. Therefore, it is very important to accurately measure the spatial distribution of the rapidly changing field strength signal.

An object of the present invention is to provide a variable sample pulse generator for receiving power measurement of a fast fading signal for receiving spatially constant data regardless of the speed change of the moving object and a receiving field strength measuring apparatus including the same.

In order to achieve the above object, the reception field strength measuring apparatus for measuring the reception power of the fast fading signal of the mobile radio signal of the present invention is an electric field strength receiver for receiving a fading signal of a mobile communication channel through an antenna, the electric field strength receiver Analog-to-digital converter (A / D converter) for converting the analog output signal of the digital signal to a digital signal, Pulse generator for providing a pulse at a constant interval according to the number of revolutions of the wheel of the moving object spatially, Measure the data of each pulse section by measuring the time interval and the amount of time change between the pulse and the pulse generator of the pulse generator so as to accurately measure the received power of the fast fading signal and to receive data at a constant spatial interval even if the speed of the moving object changes. By adjusting the time interval, the sampling rate of the analog-to-digital converter is adjusted. It includes data storage for storing the output of the position data of the digital conversion output portion of the electric field intensity data and the GPS receiving unit at the same time-varying control sample, a GPS antenna by GPS receiver, and the analog receiving the GPS data.

)은 Data measurement time interval of each pulse section (

)silver

,If n = 1,

,

이며,If n ≠ 1,

Is,

here,

n is each pulse interval generated from the moving object pulse generator after the start of data measurement,

T ₀ is the time required for the pulse section just before data measurement,

T _n is the time required for n pulse intervals,

M is the number of average data for each pulse interval, which is calculated as

Here, P is the number of pulses per one revolution of the moving wheel generated in the pulse generator,

N represents the number of sampling data to be received per revolution of the moving wheel.

The A / D converter generates data only when a pulse signal is applied by the variable sample controller, and thus does not receive a plurality of data for the stationary moving object.

Hereinafter, with reference to the accompanying drawings, it will be described in more detail with respect to the present invention.

FIG. 1 is a diagram illustrating a change in received field signal strength including path loss, long-term fading, and short-term fading along a terrain structure while the mobile station moves away from a base station. The strength of the signal that the terminal station receives from the base station while moving is shown as shown in FIG. As the terminal station moves away from the base station, the strength of the signal attenuates as a whole.

However, in the short period, even if the distance increases, the size of the signal may increase again. As shown in FIG. 1, the slowly changing component over a distance of several tens of meters is called long-term fading, and the rapidly changing signal component on slow fading is fast fading (short-term fading). It is called.

Fast fading is a fading in which signals are reflected, diffracted, and scattered by terrain, buildings, etc., and multipaths are formed. It is a phenomenon.

In order to accurately measure a fast fading signal rapidly changing in such a short distance, a sampling rate for receiving received field strength data must be high.

2 is a block diagram of an electric field strength measuring apparatus for measuring a fast fading signal of a mobile radio signal according to a preferred embodiment of the present invention.

Referring to FIG. 2, an antenna 100 receiving a mobile radio wave signal from the outside, a field strength receiver 200 receiving a fading signal through the antenna, and converting an analog output signal of the field strength receiver into a digital signal Analog-to-digital converter (A / D converter) 300, the pulse generator 400 for providing a pulse of a predetermined interval according to the number of revolutions of the wheel of the moving object spatially, the pulse generated in the pulse generator A variable sample controller 500 for adjusting the sampling rate of the analog-digital converter by calculating a time interval between a pulse and a pulse, a GPS receiver 700 receiving GPS data through the GPS antenna 600, and the analog-digital conversion. The data storage unit 800 is configured to simultaneously store received field strength data, which is a negative output, and position data, which is an output of the GPS receiver.

The pulse generated by the pulse generator becomes a trigger signal of the analog-digital converter. Whenever a pulse signal is input from the pulse generator, the analog-digital converter generates one received data.

3 is a diagram of the pulse waveform of the pulse generator of the moving object for generating four pulses per one revolution of the conventional general moving wheel.

3 is a pulse waveform of a conventional general pulse generator, and is a diagram of a pulse waveform of a pulse generator that generates four pulses per one revolution of a moving wheel. That is, a moving object pulse generating device is known which generates a pulse in a spatially constant manner according to the rotation of a wheel of a moving object that is spatially moving. 3 shows an example of a pulse waveform of a moving object pulse generator. In other words, when the moving object rotates once, four pulses are generated, and the figure shows an example of the pulse waveform of the moving object pulse generator having a moving distance of 180 cm. If the fading signal is measured by such a moving object, four data can be received while moving 180 cm. However, there is a problem in that the fast fading signal of the high frequency signal cannot be accurately measured with four received data during one rotation.

FIG. 4 is a principle presented to overcome the problems of FIG. 3. In a pulse generator in which four pulses are generated when one revolution is generated, the number of desired data is divided by the number of pulses to obtain a desired number of data per revolution. Measure the measured data between pulse intervals by the number of samples.

In the example of FIG. 4, in order to receive 40 data per wheel for a moving object having four pulses per wheel, an average of 10 data per pulse interval may be received. That is, if the time required per pulse interval is 10 seconds, one data per second may be received to receive 10 data.

However, if the speed of the moving object is not constant, the data measured at a constant time interval cannot be regarded as data measured at a constant spatial interval. Therefore, in order to increase the sampling rate of the measurement data at a constant spatial interval, correction is necessary in the principle of FIG. 4.

FIG. 5 is an algorithm of the method of the present invention proposed to solve the problem of FIG. 4 and illustrates a principle of acquiring received field strength data at a constant spatial interval even when the speed of a moving object is not constant. A more accurate fading signal can be measured so that a large amount of data can be acquired spatially and uniformly.

In the present invention, the speed of the moving moving object is one of constant speed, acceleration, or deceleration. Therefore, in order to receive data at a constant spatial interval regardless of the speed change of the moving body, the data sampling rate for the speed change of the moving body must also be varied. In other words, since the moving object moves at a high speed for a long time during the same time, the receiving data sampling rate should be fast, and the receiving data sampling rate should be reduced in the moving object speed section.

With reference to FIG. 5, the principle of the variable sample pulse generating apparatus for receiving spatially constant data regardless of the speed change of the moving object will be described.

(1) First, input the number of pulses (P) generated in the pulse generator of the moving object itself when the moving object rotates once. In this example, P = 4.

(2) Next, the user inputs the number N of sampling data to be received when the moving object is rotated once.

(3) At this time, the average number of data to be received per pulse section of the pulse generator of the moving object is calculated. That is, the number M of average data per pulse period is calculated as follows.

M is a reference data amount in all pulse sections. Therefore, the closer the number of data is to M in each pulse section, the more spatially constant data is received.

)을 측정하여, 다음 펄스 구간(n)에 적용한다.

는 초기 펄스구간의 소요시간으로, 즉 데이타 측정 직전 펄스 구간의 소요시간이며, 이것이 기준시간이 된다. 이때는 시간만 측정하고 데이터는 수신하지 않는다. (4) The time required per pulse interval of the pulse generator of the moving object (

) Is measured and applied to the next pulse section n.

Is the time required for the initial pulse section, that is, the time required for the pulse section immediately before data measurement, which is the reference time. In this case, only time is measured and no data is received.

은 각 펄스 구간의 데이터 측정 시간 간격이며, 다음과 같이 계산된다.(5, 6),

Is the data measurement time interval of each pulse interval, and is calculated as follows.

If n = 1, i.e. the data measurement time interval in the first pulse interval is

에 의해 계산된다.

Is calculated by.

If n ≠ 1, that is, from the second pulse interval

에 의해 데이터 측정 시간 간격이 계산된다. 이 식이 의미하는 바는 현재의 펄스 구간에서의 데이터 측정 시간 간격은 직전 펄스 구간의 소요시간 및 소요 시간 변화량을 고려하여 계산된다. 즉 이동체가 등속구간이냐, 가속 구간이냐, 감속구간이냐의 상태를 현재 펄스 구간의 데이터 측정 시간 산출식에 고려하는 것이므로 더 정확한 현재 펄스구간의 측정 시간 간격을 산출하게 된다.

The data measurement time interval is calculated. This expression means that the data measurement time interval in the current pulse interval is calculated in consideration of the time required and the amount of change in the time of the previous pulse interval. That is, since the moving object considers the state of the constant velocity section, the acceleration section, or the deceleration section in the data measurement time calculation formula of the current pulse section, the more accurate measurement time interval of the current pulse section is calculated.

은 n 펄스 구간에서 수신한 빠른 페이딩 신호의 수신 전계강도 데이터이다. 이 데이터를 일정한 형식에 의해 데이터 저장부에 저장한다.(7)

Is received field strength data of a fast fading signal received in n pulse intervals. The data is stored in the data storage unit in a certain format.

(8) When the next pulse of the moving object pulse generator comes in during data reception,

)을 측정하고, (5)∼(7) 과정을 반복한다.(9) Required time of previous pulse section (

), And repeat the process (5) to (7).

(10) If 'end' signal comes in during the measurement, stop the measurement at any time.

FIG. 6 shows the number of pulses P = 4 of the moving object pulse generator, the total number of data N = 400 to be received per wheel, the number of average data Ms to be received per pulse interval of the pulse generator by the algorithm of FIG. Table showing measured data table for case 100.

In this table, the same number of data as the initially set average data is received in the constant velocity section, the equal acceleration section, and the equal deceleration section, and there is a slight error in the section where the acceleration changes.

As described above, the present invention relates to a variable sample pulse generator for measuring a reception power of a fast fading signal of a mobile radio signal, and an electric field strength measuring device for measuring the strength of a received electric field according to each position. . In the mobile communication environment, it is very difficult to accurately predict the received field strength. In particular, in the radio environment where communication is mainly based on reflected waves rather than direct waves, such as urban areas, the strength of the received field strength varies greatly even if the receiving point changes only a little. As such, the prediction of the electric field strength according to the change of the surrounding environment is difficult to interpret by the general propagation model. Therefore, the empirical equations presented by measuring and analyzing the actual signals are frequently used. Therefore, it is very important to accurately measure the spatial distribution of the rapidly changing field strength signal. Receiving field strength measuring device considering the fading characteristics applying the principles and techniques proposed in the present invention can measure and analyze fading signals more conveniently and accurately, so that radio wave measuring device for wireless network design, antenna for new mobile communication and mobile communication system It can be utilized as a radio wave measuring device for evaluating the communication performance of and to determine the service area.

Claims (5)

Receiving field strength measuring apparatus for measuring the reception power of a fast fading signal of a mobile radio signal, A field strength receiver for receiving a fading signal of a mobile communication channel through an antenna; An analog-digital converter (A / D converter) for converting the analog output signal of the electric field strength receiver into a digital signal; Pulse generator for providing a pulse of a predetermined interval in accordance with the number of revolutions of the wheel of the moving object, spatially By measuring the received power of the fast fading signal of the mobile radio signal accurately and receiving the data at a constant spatial interval even if the speed of the moving object is changed, the time interval and the amount of time change between the pulse and the pulse of the pulse generator to measure each pulse A variable sample controller for adjusting a sampling rate of the analog-digital converter by adjusting a data measurement time interval of a section; A GPS receiver for receiving GPS data through a GPS antenna, and And a data storage unit for simultaneously storing field strength data output from the analog-digital converter and position data output from the GPS receiver. The method of claim 1, Data measurement time interval of each pulse section (

)silver If n = 1,

, If n ≠ 1,

Is, here, n is each pulse interval generated from the moving object pulse generator after the start of data measurement, T ₀ is the time required for the pulse section just before data measurement, T _n is the time required for n pulse intervals, M is the number of average data for each pulse interval, which is calculated as

Here, P is the number of pulses per one revolution of the moving wheel generated in the pulse generator, N is a reception electric field strength measuring apparatus, characterized in that it represents the number of sampling data to be received per one revolution of the moving wheel. The method of claim 1, And the A / D converter generates data only when a pulse signal is applied from the variable sample controller, and thus does not receive a plurality of data for a stationary moving object. In the variable sample pulse generator for adjusting the sampling rate of the analog-to-digital converter for measuring the reception power of the fast fading signal of the mobile radio signal, A pulse generator for providing pulses at regular intervals according to the number of revolutions of the wheel of the moving object spatially; By measuring the received power of the fast fading signal of the mobile radio signal accurately and receiving the data at a constant spatial interval even if the speed of the moving object is changed, the time interval and the amount of time change between the pulse and the pulse of the pulse generator to measure each pulse And a variable sample control unit for adjusting the sampling rate of the analog-digital converter by adjusting the data measurement time of the section. The method of claim 4, wherein Data measurement time interval of each pulse section (

)silver If n = 1,

, If n ≠ 1,

Is, here, n is each pulse interval generated from the moving object pulse generator after the start of data measurement, T ₀ is the time required for the pulse section just before data measurement, T _n is the time required for n pulse intervals, M is the number of average data for each pulse interval, which is calculated as

Here, P is the number of pulses per one revolution of the moving wheel generated in the pulse generator, N is the number of sampling data that you want to receive per revolution of the moving wheel, Variable sample pulse generator, characterized in that.

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